An instrument which serves to shut or open a lock.

Key

An instrument which serves to shut or open a lock.

A typewriter is a mechanical device with a set of "keys" that, when pressed, cause characters to be printed on a medium, usually paper.

Type Writing Machine

A typewriter is a mechanical device with a set of "keys" that, when pressed, cause characters to be…

Banks of keys- Boards at Saint-Sulpice. An instrument consisting of a number of pipes that sound tones when supplied with air and a keyboard that operates a mechanism controlling the flow of air to the pipes

Organ

Banks of keys- Boards at Saint-Sulpice. An instrument consisting of a number of pipes that sound tones…

The saxhorn is a brass instrument with: a, mouthpiece; b, valves; c, keys; d, bell; e, crook.

Saxhorn

The saxhorn is a brass instrument with: a, mouthpiece; b, valves; c, keys; d, bell; e, crook.

This illustration depicts the use of a key tag, using an object to aid in the identification of a key.

Key Tag

This illustration depicts the use of a key tag, using an object to aid in the identification of a key.

"A simple telegraph consisting of two telephone receivers, two batteries, and two keys." -Avery 1895

Simple Telegraph

"A simple telegraph consisting of two telephone receivers, two batteries, and two keys." -Avery 1895

"A complete telegraph system, displaying batteries, keys, receivers, relays and local batteries on both ends." -Avery 1895

Complete Telegraph System

"A complete telegraph system, displaying batteries, keys, receivers, relays and local batteries on both…